body of water vs wellhead

body of water

noun
  • Used other than figuratively or idiomatically: see body, of, water. 

  • Any significant accumulation of water, usually covering the Earth or another planet, such as an ocean, a river, lake or a bay. 

wellhead

noun
  • The source of something; a fountainhead. 

  • The surface structure of an oil well etc. 

  • The place where a spring breaks out of the ground; the source of water for a stream or well. 

How often have the words body of water and wellhead occurred in a corpus of books? (source: Google Ngram Viewer )